Portable well servicing rig



May 6, 1952 J, P, SELBERG 2,595,307

PORTABLE WELL-SERVIC'ING RIG l Filed OCT.. 9, 1946 4 Sheets-Sheet l John P Selber? Mall 6, 1952 J. P. sELBERG 2,595,307

PORTABLE WELL-SERVICING RIG Filed 001;. 9, 1946 4 Sheets-Sheet 2 ,1' ,l ll

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May 6, 1952 J. P. SELBERG 2,595,307

PORTABLE 'wELL-sERvIcING RIG Filed Oct. 9, 1946 4 Sheets-Sheet 5 me/wm Q John I? Selber-.9

@Mo/man May 6 '1952V J. P. sELBERG 2,595,307

PORTABLE WELLSERVICING RIG Patented May 6, 1952 PORTABLE WELL SERVICIN G RIG John P. Selberg, Los Angeles, Calif, assignor, by l mesne assignments, to Dresser Equipment Company, Torrance, Calif., a corporation of Ohio Application October 9, 1946, Serial No. 702,317

Claims.

The present invention deals with derrick equipment, and more specifically to mobile derrick rigs of the type employed in drilling, or otherwise servicing oil wells.

Under present day oil well operations, the need of mobile Yor portable well-servicing equipment has become increasingly apparent with the general increase in operational eiliciency and timesaving methods presented to the industry as a whole. Formerly, oil wells were provided with individual permanent derrick structures, which were manifestly a great wastage of time and money. Such lstructures necessitated erection at the scene of operations, and after their usefulness had expired, were either torn down and scrapped, or were abandoned entirely and left standing to deteriorate with time. As the industry progressed, the development of portable and prefabricated derrick equipment ensued, but such development did little to alleviate the burden of construction and erection, as such `structures were necessarily cumbersome in nature and required considerable time in their assembly and disassembly.

With the recognition of. large automotive vehicles by the industry, the problem of individual servicing equipment for the numerous oil wells has been greatly reduced, in that vehicles now transport practically all of the necessary servicing equipment directly to the scene of operations, and when such servicing has been completed, remove the necessary equipment to another Well in need of service. Hence, the equipment necessary to service a number of wells has been greatly reduced, and consequently the labor and cost, as well as the amount of equipment has correspondingly dropped.

Even with the advent of highly mechanized and mobile equipment, such as mobile derricks and the like, there still remains the need for more eiiicient and simpliiied machines in order that the task of well-digging and servicing in general may be carried out with a minimum of time and eX- pense.

Accordingly, it is an object of this invention to provide and improved mobile derrick rig embodying a mast structure which is elevated to a position of operation and depressed to a position of transportation by one or more hydraulically operated telescopic rams.

It is an additional object of the present invention to provide, in such a rig, a greatly simplified ram for the complete actuation of the mast, thereby eliminating superfluous and complicated 2?. mechanisms heretofore present in machines of this character.

Many additional objects and advantages of the present invention will become readily apparent with reference to the following description and accompanying drawings, wherein:

Fig. 1 is a side elevational View of an improved mobile derrick rig formed in accordance with the present invention;

Fig. 2 is an enlarged side elevational view of the mast in an elevated position of operation;

Fig. 3 is a fragmentary top plan View of the ram and mast-bracing disclosing their pivotal connection with the door of the associated trailer vehicle;

Fig. 4 is a diagrammatic plan View of the hydraulic system associated with the telescopic Tam;

Fig. 5 is a detailed side elevational View of the control system of the ram;

Fig. 6 is an enlarged vertical sectional view taken through the base portion of the hydraulic ram;

Fig. 6a is a similar View taken through the upper portion of the ram, and is a continuation of Fig. 6;

Fig. 7 is a horizontal sectional View taken along the line 'I-'I of Fig. 6a.

Fig. 8 is a detailed vertical sectional View taken through the poppet valve located in the base portion of the ram.

Referring now to the drawings, it will be noted that the present embodiment of this invention makes use of an automotive truck I0 having attached thereto in towing relation an elongated platform trailer II. Secured to the bed of the trailer, substantially at its rearward end, is a supporting beam I2 which projects diagonally upwardly and rearwardly of the trailer. The upper end of this beam is pivotally secured, as at I3, with an intermediate portion of a derrick mast Iii'. In addition to this beam, the mast is also supported aiong its pivotal axis by a pair of tubular side braces I5 which extend diagonally downwardly and are linked as at I6 with projecting lugs Il secured to the trailer bed.

The mast I4 is pivotally carried, in the above manner, at a position along its length which permits the lower en-d of the mast, when in an erect position, to approximately align with the horizontal plane of the surface upon which the vehicle and trailer rests.

As illustrated in Fig. l of the drawings, the mast I4 is carried by the trailer so as to swing between a prone or horizontal position of transportation, and an erect position of operation, the latter position being slightly past the vertical or dead center position of the mastl with respect to its longitudinal axis. These limits of swinging movement are respectively imposed by a cradle bracket |8 carried at the forward end of the trailer upon which the forward portion of the mast rests when in a prone position, and a spring bumper i9 projecting from the rear end of the trailer which engages the mast when it reaches an approximately vertical position. Although the spring bumper I9 has been described as limiting the swinging movement of the mast; it will be manifest, from the following detailed description, that the spring bumper may be eliminated in its entirety by the use of a push-pull hydraulic ram.

To accomplish the raising and lowering of the mast |4, a hydraulically operated telescopic ram 20 is interposed between the mast and the bed of the trailer. The ram is provided at each of its ends with links 2| and 22, respectively. The lower link 2| is pivotally connected, by means of a pin 24, with an inverted V-shaped bracket 23 projecting from the bed of the trailer The upper link 22 is also pivotally connected with the mast |4, as at 25, at a position substantially forward of its pivot point. In this manner, the ram is allowed to move freely in a plane parallel to the longitudinal axis of the trailer, as is the mast |4.

The ram 29 comprises four intertting cylinders 25, 2128 and 29, respectively. The base cylinder 26 manifestly possesses the largest diameter of the four, with each respective cylinder possessing a lesser diameter from base to top. The lower end of the base cylinder 26 is carried in threaded engagement with a circular valve housing 3| which communicates with a channel 32 formed internally of the socket 38 and opening to one side thereof. The wall of the housing 3| is formed with a plurality of relatively large open slots 33 at its lower position, and four restricted openings 34 at its upper portion. The upper end of the housing is closed by a valve base 35 which supports one end of a compression spring 36. The opposite end of the spring engages with a thimble 31 formed with an axially disposed restricted orince 38 at its lower end.

The bottom of housing 3| is provided with a packing ring 39 which forms a tapered seat for the end of the thimble 31. It will thus be seen, that uid under pressure may be introduced to the cylinder 25 by conducting the same to the 5 socket channel 32, whose outer end is threaded to receive a cooperatively threaded plug 48 secured to the end of a flexible conduit 4|, and such fluid, when flowing under pressure to the valve, will unseat the thimble 31 and pass through the largeslots 33 in a substantially unrestricted ilow into the interior of the cylinder 26. Conversely, fluid under pressure within the cylinder, when returning through the valve, will have to pass through the small restricted openings 34 and out through the orifice 38 formed in the bottom of the thimble, thus restricting the flow thereof. Consequently, the flow of fluid passing into the cylinder 2B will be unrestricted, and the flow of fluid passing out of the chamber will necessarily be restricted.

The uppermost cylinder 29 is received within a threaded socket 42 forming the lower portion of the upper link 22, which socket is provided with a duplicate valve structure of that contained in the lower socket 30. With reference to Fig. 6a, it will be noted that the entrance of fluid under pressure to the cylinder 29 will be unrestricted, but the exit thereof will be restricted in the manner of the lower valve. For ease of explanation, like parts of each of these valves bear like numerals.

As shown in Figs. 6 and 6a, the upper end of the base cylinder is externally threaded as at 43 and receives a threaded collar 44 formed with a centrally disposed opening whose diameter closely approaches the diameter of the second cylinder 21. The circular wall defining this opening is provided with an embedded annular packing gland 45 which engages the outer wall of the second cylinder to insure a liquidtight seal between the base cylinder 26 and the second cylinder 21.

The lower end of the second cylinder is open and communicates with the interior of the base cylinder 25. The lower portion of the second cylinder 21 is provided with a pair of spaced peripheral guide rings 45 which are in wiping engagement with the inner walls of the base cylinder 2G. These rings serve to support the second cylinder in axial alignment during sliding movement thereof within the base cylinder. Each of these rings are provided with a series of spaced grooves 41 which allow uid to pass freely therethrough when the cylinders are in relative motion.

The third cylinder 28 is maintained within the second cylinder by a similarly formed collar 48, and is aligned in the exact manner as is the cylinder 21 by guide rings 49. The third cylinder, however, is provided with a closure plate 50 at its lower end, which plate is formed with a centrally disposed restricted opening'A 5|. It will be seen, that as fluid enters freely through the valve disposed at the lower end of the ram, when the same is in a retracted state, as shown in Fig. 1, the pressure created thereby will act on elements 21, 28 and 29 to cause them to all emerge as one group until 46 engages 44. Then elements 28 and 29 emerge as one Vgroup until 49 engages 48. Finally, 29 emerges.

The lower end of the fourth and uppermost cylinder 29 is held within a screw-threaded socket of a circular piston 52 whose outer wall is maintained in wiping engagement with the inner wall of the third cylinder. The outer wall is also provided with an annular packing gland 53 which forms a liquid-tight seal between the outer wall and the inner wall of the third cylinder. Thus, it will be seen that fluid under pressure within the third cylinder will react against the piston 52 and tend to extend the fourth cylinder 29. To provide for the Venting of fluid within the cylinder 28 above the piston, a series of circular openings 54 are formed in the walls of the fourth cylinder just above the piston 52. `While specific types of packing have been disclosed in the drawings, it will be manifest that any suitable means may be employed in maintaining the various cylinders in a liquidtight condition.

It will be noted that the end of the third cylinder 28 is provided with a collar 55 of the same type utilized on the other cylinders, and fluid present between this collar and the piston 52 will be vented through the openings 54 into the cylinder 29 as it is raised within the third cylinder 28. When the fourth cylinder has become completely extended, the fluid present therein will pass through the upper valve, which is seated by the pressure of the fluid, and will pass in a restricted flow out of the ram and through the upper flexible conduit 4I.

With the ram in an extended condition, and it is desirable to retract the same, the direction of fluid flow is reversed, that is, the lower flexible conduit 4l is vented, and iiuid under pressure is supplied to the ram through the valve disposed in the top of the fourth cylinder 29. This flow will cause the fourth cylinder to retract within the third cylinder, at which time the mast I4 will swing forward past dead center, or the vertical, and its weight will react against the support of the ram to force the fluid present therein out of the lower valve in a restricted flow and cause the ram to fully retract at a relatively slow rate.

From the preceding description, it will be understood that the ram is of a so-called three stage type, with the first two stages single-acting and the third stage double-acting, as the extension and retraction of the second and third cylinders is controlled by the flow of uid through the lower end of the ram, while the extension and retraction of the fourth or top cylinder relative to the third cylinder is controlled only by the ow of fluid through the upper end of the ram. Due to the action of the individual valves, the eX- tension of the fourth cylinder 29 is relatively slow, as is the retraction of the second and third cylinders. This is a highly desirable feature, as the relatively slow extension of the fourth cylinder serves to snub the mast as it swings past a vertical position into its slightly inclined position of operation, as shown in Fig. 2 of the drawings; also, the relatively slow retraction of the second and third cylinders serves to snub the mast as it swings back past a vertical plane, and to lower the same at a safe speed to its prone position of transportation.

While the drawings disclose a valve structure disposed in the upper cylinder 29, it will be understood that the operation of the ram will in no way be impaired by replacing the necessarily expensive valve structure with a single fixed restricted orifice. Such an orifice will serve with equal efhciency to snub the mast as it passes dead center in either direction.

Due to the snubbing action during the extension of the fourth cylinder, and to the fact that the fourth cylinder when reaching its maximum position of extension will substantially supply a rigid brace for the mast, it will be understood that the spring bumper I9 which projects from the rear end of the trailer may be eliminated.

In former devices of this character, such a bumper was absolutely necessary to the operation of the machine, as it was necessary to afford means of returning the mast to a position past dead center, when utilizing a single stage hydraulic ram. Such single stage rams only serve to erect the mast, and it was necessary to employ either a spring-tension bumper or a hydraulically operated bumper to return the mast back past the vertical position. This auxiliary equipment was manifestly expensive and offered numerous maintenance difficulties. The spring bumper l 9, as described, serves merely as a resilient stop for the mast, and should in no way be interpreted as a return mechanism therefor. If desired, this spring may be entirely eliminated in future constructicns without departing from the spirit of the present invention.

Referring now more particularly to Fig. 4 of the drawings which discloses in diagrammatic form the control system for supplying and regui R. D. L. valve.

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lating the flow of fluid to the ram 2G, it will be noted that the exible conduits joining with the respective ends of the ram are supplemented by and joined with rigid conduits where no ilexibility is required. Both of these conduits extend forwardly of the trailer and separately join with a four-way control valve 56, commonly known to those familiar in the art, as a Vickers No. 2330 This type valve includes a single operating lever 51 having three operating positions which respectively provide for the iiow of uid to the lower end of the ram and the simultaneous venting of the upper end of the ram, the flow of iiuid to the upper end of the ram and the simultaneous venting of the lower end, and the locking of both ends of the ram with respect to the flow of fluid therein.

The system further includes a reservoir tank 53 which is suitably vented to the atmosphere, and which stores a suitable quantity of hydraulic liquid. A lead line 59 is connected with the bottom of the tank and serves to conduct liquid under gravity flow to a lter 6U where foreign particles in the liquid are removed before the liquid is conducted to a force pump El. From this pump, the liquid is conducted under suitable high pressure, which may vary between 500 to 2000 pounds per square inch, to the four-way valve 56. The conduit between the pump 6l and the valve is provided with a check valve 62 which prevents ram fluid from returning to the tank through the pump when the latter is not operating.

The conduit leading from the four-way valve 56 to the lower end of the ram 2l) is provided at stages with a high pressure gauge 63, a pressure relief valve 64, and a thermal relief valve 65, all of which serve to indicate or control the pressure and iiow of the liquid to and from the lower end .of the ram 2li. The four-way valve 56 is further provided with a return-flow conduit 66 which is joined with a low-pressure relief valve 67 and an associated low-pressure gauge 68, and empties into the top of the tank 58. The portion of the hydraulic system, including the thermal relief valve 65 and low pressure gauge 68, provides for the thermal expansion of ram fluid only, and affords relief for the system during thermal expansion of the hydraulic fluid within the ram.

Detailed description of the various valves utilized in this system has been eliminated, as their functions and structure are well known to those skilled in the art of hydraulics, and the control system as a whole is merely an aggregation of known and previously used parts. The functioning of the control system serves merely to control the operation of the ram 20 in the most simple and efficient manner, and it should be understood that numerous variations in such a system are possible without departing from the l spirit of this invention.

As shown in Fig. l of the drawings, an internal combustion engine 69 is mounted on the trailer bed, and serves to supply power in driving the force pump 6l of the hydraulic system, and in operating additional mechanisms, such as a winch 'l0 used in conjunction with a hoist carried by the mast.

The present invention, it will noted, thus provides a readily portable well-servicing mast or derrick which may be conveniently moved from place to place and set up for active operation. Through the use of the telescopic hydraulically controlled ram, convenience and security are obtained in the raising and lowering of the mast.

The particular feature resides in the dual action provided in the extension and retraction of the ram.

While a specic embodiment of the present invention has been described as a present preferred form, it will be manifest that various modications in details of construction are possible without departing from the scope of the following claims.

I claim:

1. In a portable derrick rig including a mobile base having a mast pvotally carried thereby, a hydraulically operated extensible ram for raising said mast to swing past a vertical position and for lowering the mast to a non-vertical position, said ram being connected between said base and said mast and comprising a plurality of telescoping sections including a top section, a bottom section, and at least one intermediate section therebetween, each-of said top and bottom sections being provided with means for entry and discharge of hydraulic fluid, the top section comprising a hollow cylinder which is spaced from an intermediate section telescoping therewith by relatively spaced flange means carried on the respective sections and defining a closed chamber between said top section and said intermediate section, said cylinder having a pressure reaction surface at its lower end and an opening above itS lower end communicating with said chamber, I

said cylinder having a restricted oriiice at its upper end whereby fluid temporarily trapped in said chamber and in said hollow cylinder is effective to snub the extension of said top section relative to said intermediate section, and means in one of the sections of said ram other than said top section to snub the retraction of all of said sections.

2. In a portable derricl; rig including a mobile base having a mast pvotally carried thereby, a hydraulically operated extensible ram connected between said base and said mast and comprising a pair of telescoping end sections and at least one intermediate ytelescoping section therebetween, one of said end sections and an intermediate section defining telescoping cylinders having a space therebetween closed at both ends and dened by spaced flanges on the respective sections; vent means in said one of said end sections communieating with said space, said last-named end section having a restricted uid outlet above said vent means and a pressure reaction surface below said vent means, means for introducing iluid into the other of said end sections to extend the opposite end section and an intermediate section f relative to said other end section and to cause the aforesaid space to become smaller and thereby to cause huid in said space to pass through said vent means and the restricted fluid outlet to thereby snub relative extension movement between the end section having the restricted fluid outlet and said intermediate section; means :for introducing pressure fluid into the space between the end section containing the restricted outlet and said intermediate section to react upon the ilanges of said sections and thereby to cause relative retraction movement therebetween; and restricted orice means in the other of said end sections to snub retracting movement of an intermediate section with respect thereto.

3. In a portable derrick rig having a mobile base and a mast pvotally connected with said base for swinging movement between substantially horizontal and vertical positions; a :duidpressure-actuated ram connected between said base and said mast and operable to swing the latter between substantially horizontal and vertical positions, said ram comprising a plurality of telescoping, relatively extensible sections including a rst end section connected with said base, a second end section connected with said mast, and at least one intermediate section .between said end sections, one of said end sections having a luid-pressure-reaction surface thereon defining with a cooperative iuid-pressure-reaction surface on an intermediate section a conned pressure chamber; restricted orifice means in fluid communication with said pressure chamber whereby, upon relative extension movement between said last-named end section and said intermediate section, huid will be temporarily trapped in said chamber and vented through said orifice means to snub relative extension movement between said last-named end section and said intermediate section; and restricted outlet means in fluid communication with the opposite end section for snubbing retraction movement of all of said sections.

4. In a portable derrck rig including a mobile base having a mast pvotally carried thereby; a uid-pressure-actuated extensible ram connected between said base and said mast and operable to raise said mast from a substantially horizontal position to an inclined position slightly past a vertical position and to lower said mast from said inclined position to said substantially horizontal position, said ram comprising a base section connected with said mobile base, at least one intermediate section telescoping with said base section, and an outer end section pvotally connected with said mast and telescoping with at least one intermediate section, said outer end section having a pressure reaction surface on its inner end, each of said base and outer end sections being provided with iluid inlet-outlet ports, said intermediate and outer end sections being movable outwardly with respect to said base section and with respect to each other in response to the introduction of pressure fluid within the inletoutlet port of said base section to raise said mast, and said outer end section being movable inwardly of at least one intermediate section in response to the introduction of pressure iiuid within its inlet-outlet port to swing said -mast from a past vertical position to a position short of vertical; means in said outer end section to snub outward movement thereof only with respect to the adjoining intermediate section, said means comprising a restricted orifice at the top of said outer end section and vent means near the bottom of said outer end section, said vent means communicating with Va comined space between the outer end section and the adjoining intermediate section dened by relatively spaced flange means on said outer end section and said intermediate section, whereby fluid will be temporarily trapped in said outer end section and said space upon outward movement of said outer section; and means including a restricted orice in communication with the inlet-outlet port of said base section to snub inward movement of said intermediate and outer end sections with respect to said base section.

5. In a portable derrick rig including a mobile base having a mast pvotally carried thereby, a hydraulically operated extensible ram for raising said mast to swing past a vertical position and for lowering said mast to a non-vertical position, said ram being connected between said base and said mast and comprising a plurality of telescop-` ing, relatively extensible sections including a iirst end section connected with said base, a second end section connected with said mast, and at least one intermediate section between said 'end sections; relatively spaced flange means carried, respectively, on one of said end sections and an adjacent intermediate section and defining between said last-named sections a confined pressure chamber, said flange means providing pressure reaction surfaces on said last-named end section and intermediate section, said last-named end section being hollow and provided with vent means communicating with said chamber; restricted orifice means positioned in the outer end portion of said last-named end section and communicating with said chamber by way of said vent means for restricting ilow of uids outwardly of said chamber and said last-named end section and thereby to snub the extension of said lastnamed end section relative to said adjacent intermediate section; and restricted outlet means in the other of 'said end sections for snubbing retraction movement of all of said sections.

' JOHN P. SELBERG.

" REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS 

